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Signature ✍️
- Infiltration of the adventitia of large & medium arterial vasculature (”periarteritis”)
- Cross-sectional imaging revealing “circumferential thickening” vs. “soft tissue” mass encasement of large & medium arterial vasculature (i.e. aorta → coronary, mesenteric, & iliac arteries)
↓ ↓ ↓
⚪ If the “soft tissue” mass enhances in the late post-contrast phase, this is described as the “mantle sign”
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DDx 🏳️🌈
Autoimmune
- IgG4-RD
- ANCA-associated vasculitis
- Takayasu arteritis & GCA
- Cogan syndrome
Infectious
- Syphilis
- Tuberculosis
Malignant Histiocytoses
- Erdheim Chester Disease
- Rosai Dorfman Disease
Local Malignancy
- Angiosarcoma
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Principles❗️
“Vascular Encasement” as a Manifestation of Vasculitis
- “Vascular encasement” represents one of the less morbid manifestations of large & medium vessel vasculitis, as clinical complications of pure uncomplicated encasement include only those of vascular stenosis (e.g. claudication, chronic mesenteric ischemia) vs. extravascular compression (e.g. hydronephrosis)
- On the opposite end of this spectrum, more morbid manifestations of large & medium vessel vasculitis include the acute aortic syndromes (i.e. aneurysms prone to rupture, dissections) owing to contiguous inflammatory destruction of the vascular media’s elastic fibers & intima (which are more routinely affected in primary vasculitis)
Diagnosis
- If serologic work-up is ⊖ (i.e. syphilis & ANCA screen), reaching the endpoint diagnosis can be quite challenging, as tissue diagnosis requires sampling very dangerous sites (i.e. high risk of hemorrhage)
- In such cases, step #1 is to look elsewhere for potential tissue sites (e.g. PET scan → bone biopsy if histiocytosis lesions)
- If no extra-vascular tissue sites are available for sampling, empiric immunosuppression with a therapeutic response may provide an answer:
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References 📚
